1. Field of the Invention
The present invention relates to a zoom lens and an imaging apparatus, and more particularly to a zoom lens that is suitable for use with digital cameras, video cameras, motion-picture cameras, broadcasting cameras, monitoring cameras, etc., and an imaging apparatus provided with the zoom lens.
2. Description of the Related Art
As zoom lenses having a four- or more group configuration that is applicable to imaging apparatuses of the above-described fields, those disclosed in Japanese Patent No. 4463909 and Japanese Unexamined Patent Publication Nos. 2012-189817 and 2009-198656 (hereinafter, Patent Documents 1, 2, and 3, respectively), for example, have conventionally been proposed. Patent Document 1 discloses a zoom lens that consists of, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group, and a fourth lens group having a positive refractive power, wherein, during magnification change from the wide-angle end to the telephoto end, the first lens group and the fourth lens group are fixed relative to the image plane, and the second lens group and the third lens group are moved relative to the image plane. Patent Document 2 discloses a zoom lens that consists of, in order from the object side, a first-a lens group having a positive refractive power, a first-b lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power, wherein, during magnification change from the wide-angle end to the telephoto end, the first-a lens group and the fourth lens group are fixed relative to the image plane, and the first-b lens group, the second lens group, and the third lens group are moved relative to the image plane. Patent Document 3 discloses a zoom lens that consists of, in order from the object side, a first lens group having a positive refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, a fourth lens group having a positive refractive power, and an imaging group, wherein, during magnification change from the wide-angle end to the telephoto end, the first lens group and the imaging group are fixed relative to the image plane, and the second lens group, the third lens group, and the fourth lens group are moved relative to the image plane.